Following is a step by step tutorial on how I do my in-seam pockets. Of course there might be other better ways but this is how I do it.
Start with 4 pcs of pockets all cut and serge or zig-zag around the curvy edges of all the pieces
Turn the pocket to the side seam, right sides together and pin. Ensure that the pocket is placed at the same distance from the waist for all 4 pockets.
Sew the pocket to the side seam using a 3/8" seam allowance, back stitch both the beginning and end.
If you have any questions please to do hesitate to leave me a comment.
I will be conducting the Moji Pants class at Yee Button on 20th February 2016 (Saturday). For more info please click my Facebook Event Moji.